Method for the rapid and continuous dyeing of mixtures of textile materials

ABSTRACT

TEXTILE MATERIALS AND FILMS ARE RAPIDLY AND CONTINUOUSLY DYED BY SUBJECTING THEM TO THE ACTION OF A HOT AQUEOUS DYE LIQUOR CONTAINING BENZYL ALCOHOL WHEN THE TEXTILE MATERIAL IS NYLON OR POLYESTER, PROPYLENE CARBONATE OF DIPROPYLENE CARBONATE (ESPECIALLY THE LATTER) WHEN THE TEXTILE MATERIAL IS ACRYLIC, OR WOOL; OR A MIXTURE OF BENZYL ALCOHOL AND PROPYLENE CARBONATE OR DIPROPYLENE CARBONATE (ESPECIALLY THE LATTER) WHEN THE TEXTILE MATERIALS IS A MIXTURE OF NYLON OR POLYESTER WITH ONE OF THE OTHERS JUST NAMED, INCLUDING WOOL.

Jan. 26, 1971 J. HERMES METHOD FOR THE RAPID AND CONTINUOUS DYEING OFMIXTURES OF TEXTILE MATERIALS Filed May 8, 1968 l DYED TEXTILE MATERIALINLET FORv TEXTILE MATERIAL TO BE DYED l1 l 1111 f r/ lll lll /l Il WSTIE mm VE mH S m L Uv lb DI M U 4nul ATTORN .5

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mit .vz f I* l'.. fh -I I.I U n L United States Patent O 3,558,260METHOD FOR THE RAPID AND CONTINU- OUS DYEING OF MIXTURES OF TEXTILEMATERIALS Julius Hermes, 905 Jefferson Circle, Martinsville, Va. 24112Filed May 8, 1968, Ser. No. 727,388 Int. Cl. D06p 3/82 U.S. Cl. 8-21 2Claims ABSTRACT F THE DISCLOSURE Textile materials and films are rapidlyand continuously dyed by subjecting them to the action of a hot aqueousdye liquor containing benzyl alcohol when the textile material is nylonor polyester, propylene carbonate or dipropylene carbonate (especiallythe latter) when the textile material is acrylic, or wool; or a mixtureof benzyl alcohol and propylene carbonate or dipropylene carbonate(especially the latter) when the textile material is a mixture of nylonor polyester with one of the others just named, including wool.

The present invention relates to the rapid and continuous dyeing oftextile materials and films and also to an apparatus especially usefulin achieving those dyeing results.

Those familiar with the art of dyeing are well acquainted with themultitude of processes for the continuous dyeing of'textile materialsand films and therefore will appreciate the simplicity of the processesdescribed hereinafter, as well as the simple and comparativelyinexpensive apparatus especially adapted to bring about those dyeingresults.

` It has been established that the continuous dyeing methods in usetoday are only adaptable for certain types of synthetic materials andare valueless for other synthetic materials or textiles made fromnatural fibers. For instance: the so-called Thermosol Process and themachinery used for that process are only adaptable for synthetics wherea migration of color into the fiber through heat can be obtained.Therefore, the Thermosol Process is mostly used for textile materialscomposed of polyester and can only be used in conjunction with disperseddyestufis. Dispersed dyestuffs show the ability to migrate from acoating into the polyester material. Reference to polyester here andelsewhere throughout the specification and claims is to be taken asreferring to conventional polyethylene terephthalate, which may or maynot be modified in ways per se well known to the art.

Another dyeing method is to penetrate a textile material or film with asolution of certain suitable dyestuffs and then subsequently expose thethus-treated textile material or film to steam. This steaming cycle isvery timeconsuming, and it can readily be seen that in order to achieveconsiderable production large size steamers are necessary. 'Iliis isespecially the case in dyeing 15 feet width carpets by either of theaforementioned methods.

In practice it has also been found that considerable difficulties areencountered due to unevenness of the color across the width of thematerial. This defect is especially apparent in the continuous dyeing of15 feet width carpets. Withthe existing continuous dyeing methods it isvery difficult to dye satisfactorily to dark and full shades. It isfurther difficult to dye continuously textile materials composed ofmixtures of various synthetics or natural fibers. It lwill beappreciated from the following disclosure of my processes and from thedescription of my new and improved dyeing apparatus that theseaforementioned difiiculties are eliminated.

For instance: I have found that when a commercial polyester material istreated as described in my U.S. Patent No. 2,938,811, issued May 3l,1960, such treated ice polyester materials may readily be dyedcontinuously and rapidly in an aqueous dyebath containing a suitabledyestuff and certain swelling agents for the polyester material. I havealso found that the dyeing time may be as short as 10 seconds toaccomplish fully penetrated dyeings. In the case of very dark dyeings,however, it may be advantageous to increase the dyeing time somewhat. Ihave discovered that a good deep black requires a dyeing time of only 40seconds.

In order to achieve rapid dyeing time with polyester materials, it isnecessary to use a suitable swelling agent in the aqueous dyebath.Suitable swelling agents I have tried were phenolic compounds,resorcinol, dibenzyl ether emulsion, benzyl alcohol, and banzyl alcoholemulsions. However, I do not wish to limit myself to the use of theaforementioned swelling agents for polyester materials.

I have found that the best results were obtained with benzyl alcohol asthe swelling agent for polyester textile material.

For instance: A skein of polyester yarn, pre-treated in accordance to myU.S. Patent No. 2,938,811, was dyed for 10 seconds at the boil in adyebath containing:

water-500 cc. Igepon T (dispersing agent)-1 gram C. I. Disperse Red 55-1gram The outcome of this dyeing was a light red.

When to the same dyebath I added 5% benzyl alcohol and dyed anotherskein of polyester yarn under the same conditions as mentioned before,the resulting dyeing was a dark and full red.

I finally discarded the use of all phenolic compounds as swelling agentsfor the polyester material due to the adverse effect on the fastnessproperties. These adverse effects follow from the fact that the phenoliccompounds can only be removed with difiiculty by heating the polyestermaterial, after dyeing, during the final drying operation to very hightemperatures such as 380 F., and if all traces are not removed the lightfastness is adversely affected. Moreover, aside from the adverse effecton the polyester material itself, one of the most serious side effectsfrom the use of these phenolic compounds is the contamination of thedischarge wash water containing them, with the ultimate contamination ofour rivers and streams.

Another skein of polyester yarn, pre-treated according to my U.S. Pat.No. 2,938,811, was dyed for 10 seconds at a boil in a dyebathcontaining:

Water--SOO cc.

Igepon T-l gram Resorcinol-ZS grams C.I. Disperse Red 55-1 gram Thisdyeing was considerably darker than the dyeing without a swelling agent,as described above, but not quite as dark as the dyeing with benzylalcohol as swelling agent.

Another skein of a polyester yarn, pre-treated according to my U.S. Pat.No. 2,938,811, was dyed under the same conditions as above in a dyebathcontaining:

Water- 470 cc.

Dibenzyl ether-ZS cc.

Emulsifier (Lyogen CW-40, an ethylene oxide condensate manufactured bySandoz)-5 grams C.I. Disperse Red 55-1 gram This dyeing showed the sameresult in depth of color as the dyeing with benzyl alcohol. Althoughdibenzyl ether is considerably cheaper than =benzyl alcohol, I preferthe use of benzyl alcohol due to its greater ease of handling.

Since dibenzyl ether is water-insoluble, it is very difficult to removefrom the polyester material unless an emulsifier is also used.

I have also discovered that textile materials or articles composed ofacrylics, such as Orlon, Acrilan or Lucite, may be dyed rapidly andcontinuously in a matter of seconds into full and dark shades. Hereagain I make use of a swelling agent for the acrylic material in orderto accelerate the dyeing process. Of the various swelling agents tested,I have found that propylene carbonate and dipropylene carbonate are themost suited as swelling agents for acrylic materials. Of thesecarbonates, dipropylene carbonate is preferred due to its heatstability. The dipropylene carbonate is employed in the form of anaqueous solution. During the course of my research I discovered thatpropylene carbonate, especially when the dyebath is acidied, tends todecompose very rapidly, thus losing its effect as a potent swellingagent for acrylic materials. Therefore when propylene carbonate is to beused, the acrylic textile material is preferably impregnated with asolution containing propylene carbonate at room temperature and then theimpregnated textile material is exposed to steam.

A skein of Orlon was dyed in seconds at the boil, using a dyebathcomposed of:

Water- 450 cc. Dipropylene carbonate-50 cc. C.I. Basic Red 14-1 gram Theresulting dyeing was a full brilliant red. Standard fastness testsperformed on this dyeing showed the same fastness properties as withOrlon dyed conventionally to the same depth of shade with this samedyestuff.

I also found that by increasing the dyeing time I could reduce theamount of dipropylene carbonate proportionately. For instance, a skeinof Orlon was dyed in seconds at the boil using a dyebath composed ofWater-475 cc. Dipropylene carbonatecc. C.I. Basic Red 14-1 gram Thisdyeing matched the previous dyeing in all respects including thefastness properties.

For light and pastel shades the amount of dipropylene carbonate may befurther reduced. In practice it is unnecessary to exceed the use of 10%dipropylene carbonate in the aqueous dyeing solution even for darkdyeings. However, I do not wish to limit the amount of dipropylenecarbonate that may be used to 10% inasmuch as the precise concentrationin any given case is dictated primarily by economic considerations.

I have further found that dipropylene carbonate has the same beneficialeffect in the dyeing of wool as it has in the dyeing of acrylicmaterials. The effect of dipropylene carbonate on wool is not fullyunderstood by me but apparently it must have a swelling effect on thewool, thus allowing the dyestuff to penetrate the fiber rapidly.

As an example, a wool skein was dyed for 20 seconds at a boil in adyebath containing:

Water-450 cc. Dipropylene carbonate-50 cc. C.I. Acid Blue 25 C.I.62055-1 gram The outcome of this dyeing was a full deep blue shade. Thisdyeing showed the same fastness properties as a sample dyedconventionally with the same dyestuff with the same depth of shade.

Another wool skein was dyed for 20 seconds at the boil with apre-metallized acid dyestuff in a dyebath containing:

Water-450 cc.

Dipropylene carbonate-50 cc.

C.I. Acid Brown 45-l gram The resulting dyeing was a good full reddishbrown shade, with the same fastness properties as a sample dyedconventionally with the same dyestuff with the same depth of shade.

I have also found that by preparing a dyebath with a mixture of benzylalcohol and dipropylene carbonate and fil with the use of a properdyestufthaving affinity to both wool and nylon, a perfect union dyeingof the two fibers resulted.

For example: One skein of wool and one skein of nylon (Type 6) were dyedsimultaneously for 20 seconds at the boil in a dyebath containing:

Water- 425 cc.

Benzyl alcohol- 25 cc.

Dipropylene carbonatecc.

C.I. Acid Red 88 C.I. 15620-1 gram The resulting dyeing was a dee predwith the same depth of shade on the wool as on the nylon.

I have also found that a textile material composed of wool andpolyester, pre-treated as described in my U.S. Pat No. 2,938,811, may bedyed in the same dyebath into a union shade. A fabric composed of wooland 4,5% polyester, pre-treated according to my U.S. Pat. No. 2,938,811,was dyed for 20 seconds at the boil in a dye bath containing:

Water-425 cc.

Benzyl alcohol-25 cc.

Dipropylene carbonate-50 cc.

C.I. Acid Violet 12 C.I. 18075 (to dye the WOOD-0.25

gram

C.I. Disperse Violet 17 (to dye the polyester)-1 gram The result of thisdyeing was a bluish red with an excellent union dyeing between the wooland the polyester.

A skein of wool and a skein of acrylic material, such as Orlon, weredyed simultaneously for 20 seconds at a boil in a dyebath containing:

Water-450 cc.

Dipropylene carbonate-50 cc.

C.I. Acid Blue 15 C.I. 42645 (for the wool)-O.5 gram C.I. Basic Blue 22(for the Orlon)-0.2 gram The resulting dyeing was a bright blue shadeand showed a good union between the wool and the Orlon.

In order to bring about the best dyeing results in carrying out theaforementioned process, I have designed an apparatus especially usefulfor that purpose although it is not limited thereto.

In order to achieve perfect dyeing, it is necessary to create anequilibrium between the dyestuff in the dyebath and the dyestuffdeposited on the textile material.

In all continuous dyeing apparatus working on the dyestuff exhaustprinciple, it has been found that the dyestuff is exhausted out of thedyebath more rapidly than it can be replenished. This defect results instreaky and uneven dyeing.

The principle of my dyeing apparatus is to move the dye liquor throughthe apparatus at a much higher speed than, and in the same direction as,the textile material undergoing dyeing. Due to the relatively higherspeed of the concurrently flowing dye liquor, it becomes possible tofeed sufficient dyestuff to maintain an equilibrium while the materialpasses through the dyeing apparatus. Preferably, turbulent ow conditionsfor the dye liquor are maintained substantially throughout at leastthose portions of the apparatus where the dyeing takes place.

The accompanying drawing shows a dyeing apparatus especially designedfor the continuous dyeing of carpets of considerable width. However, itis to be understood that the apparatus can also be arranged toaccommodate less bulky materials such as dress goods and suitings.

As shown in the drawing, which is schematic and partly in verticalcross-section, Z is a funnel-shaped container adapted to contain the hotdye liquor which is circulated through the dyeing apparatus in the samedirection as the textile material. The funnel-shaped container 2converges toward a region of relatively restricted crosssection at 4which in turn leads into a sinuous chamber 6 which (as shown) mayconsist of a pair of U-shaped members connected serially in such fashionas to constitute the main treating chamber 6 through which the textilematerial undergoing dyeing passes in a tortuous path.

The funnel-shaped container 2 is closed by a removable top seal 8 whichfits into the funnel and which contains a pair of Teon lips 10 throughwhich the wide carpet or other textile material passes into the dyeingapparatus. The Teon lips 10 prevent the dye liquor circulating in thesystem from rising above the seal 8.

By way of illustration of specific dimensions that are suitable, thebottom of the funnel-shaped container 2 converges at the point 4 to whatis, in effect, a slot which may e.g. be about l in width.

The textile material undergoing dyeing, for example a l5-ft. widthcarpet 12, is introduced via the T etlon lips into the dyeing apparatusand passes downwardly beneath and around an elongated guide roller 14and through the remaining legs of the treating portion 6 of the dyeingapparatus by a succession of elongated mide rollers 16 and 18. Thecarpet or other textile material 12 then passes upwardly from the lastopen leg of the dyeing apparatus and out of the dyeing apparatus betweena pair of squeeze rollers 20` which serve to assist in keeping thetextile material moving properly through the apparatus and also forremoving excess dye liquor adhering to the treated textile material.

In addition to the squeeze rollers 20, air -knives (not shown) may bepositioned adjacent the squeeze rollers in such a manner as to bloweither cool or heated air upon the emerging textile material in orderstill further to assist in removing excess dye liquor from the dyedtextile material.

Referring now to the main portion of the dyeing apparatus at the legs 6,6, 6, 6, the thickness in horizontal cross-section is preferably thesa-me as that at the point 4, namely, about 1". This leaves, in the caseof dyeing a carpet or other textile material which is about 1/2 thick,approximately 1A" on each side of the carpet as it moves through thedyeing apparatus for the proper circulation of the hot dye liquor. Thetotal length of the treating chamber 6, 6, 6, 6 is about 20 feet.

The circulation system for the hot dye liquor 22 includes a pair ofconduits 24 for introducing hot dye liquor into the upper portion of thefunnel-shaped container 2 from a suitable manifold 26. Manifold 26receives hot dye liquor from pipe 28 leading from pump 30, whichconveniently takes the form of a high velocity liquid circulating pumpreceiving hot dye liquor from the heater 32. The circulating dye liquorenters the heater 32 by means of a suitable metering pump 34 which isfed from dye liquor sump 36, Additional or makeup dyestui liquor isintroduced into the sump 36 via inlet conduit 38 when and as required inresponse to a conventional float control valve arrangement 40. The sump36 receives circulating dye liquor from the discharge end of the dyeingapparatus 6 from which it overflows via conduits 42, 44 and 46. Theupper end of the last leg 6 of the dyeing apparatus may be extendedupwardly to a point well above the normal level of the liquid therein,in order to facilitate proper circulation of the hot dye liquor.

In operating the dyeing apparatus, guide rollers 14, 16 and 18 as wellas squeeze rollers 20 are positively driven (by conventional means notshown) in such a manner as to minimize all lengthwise tension in thecarpet or other textile material undergoing the dyeing treatment. Inother words, the relative speeds of these rollers are adjusted in such amanner that the path of the textile material between successive guiderollers is essentially a straight line while at the same time avoidingexcessive tension on the textile material.

By increasing or decreasing the speed of the high velocity liquidcirculating pump 30, it is possible readily to increase or decrease therate of liquid flow into the funnel-shaped container 2 and hence therate of liquid flow through the dyeing apparatus itself. In this way,the hot dye liquor is caused to circulate through the system at a linearrate which is a predetermined multiple of the speed of the carpet orother textile material undergoing the dyeing operation. For example, ifthe carpet or other textile material is passed through the dyeingapparatus at the rate of (say) approximately 60 feet per minute, it isreadily possible by means of a suitable adjustment to the pump 30 andthe pump 34 to create an overall circulation rate for the hot dye liquorthrough the apparatus of (say) about 600 linear feet per minute. Thishigh speed concurrent flow of the hot dye liquor in relation to the rateof travel of the carpet or other texitle material undergoing dyeingcreates highly turbulent conditions of liquid flow, thus assuringthorough penetration of the hot color solution into and through thetextile material. Due to this relatively high linear rate of flow of thehot dye liquor, it becomes a very `simple matter to maintain anequilibrium between the dyestuff in the rapidly moving dye bath and thedyestutf deposited on the more slowly moving carpet or other textilematerial. For example, good results are obtained when the carpet orother textile material is passed through the dyeing apparatus at speedsof from about l0 to 60 yards per minute. The correlative linear speedsfor the circulation of the hot dyeing liquor flowing concurrentlythrough the apparatus are of the order of about 2 to 10 times that ofthe textile material, measured in the most restricted portions (i.e. thevertical portions) of the legs 6, 6, 6, 6 of the treating apparatus.

Although the preferred temperature of dyeing is with the aqueous dyebathat or close to the boil, somewhat lower temperatures may be employed ifdesired with somewhat less desirable results. Thus, aqueous dyebathtemperatures as low as F. may be resorted to, if desired. Generallyspeaking, however, dyeing temperatures at or near the boil, ie.e., inthe range of about 208 to 212 F. are preferred.

What is claimed is:

1. In a method for the rapid dyeing of textile materials comprising amixture of wool and a polyester at ele vated temperatures by means of acolor solution comprising an aqueous solution of a suitable dyestuif,the improvement comprising employing as the color solution an aqueoussolution containing the dyestulf and, as a swelling agent, a mixturecomprising dipropylene carbonate and benzyl alcohol.

2. In a method for the rapid dyeing of textile materials comprising amixture of wool and a nylon at elevated temperatures by means of a colorsolution comprising an aqueous solution of a suitable dyestutf, theimprovement comprising employing as the color solution an'aqueoussolution containing the dyestuff and, as a swelling agent, a mixturecomprising dipropylene carbonate and benzyl alcohol.

References Cited OTHER REFERENCES H. V. Schmidlin, Preparation andDyeing of Synthetic Fibers, 1963, Publ. Chapman & Hall Ltd., London, pp.152-155, 159.

H. C. Speel, Textile Chemicals and Auxiliaries, 1957, ReinholdPublishing Corp., New York, pp. 280, 281, 299, 300.

E. R. Trotman, Dyeing and Chemical Technology of Textile Fibers, 1964,Publ. Griin, London, p. 521.

GEORGE F. LESMES, Primary Examiner T. I. HERBERT, JR., AssistantExaminer

